CH12 animal diseases

Question 1

Tuberculosis

Answer 1

• bacteria
• damages and destroys lung tissue and suppresses immune system
• body less able to defend off other diseases
• curable by antibiotics and preventable by vaccination

Question 2

Bacterial meningitis

Answer 2

• bacterial infection of the meninges of brain
• can spread to rest of body causing septicaemia and rapid death
• antibiotics can cure if delivered early
• vaccines can protect against some forms

Question 3

HIV/AIDS

Answer 3

• virus
• gradually destroys immune system so affected are open to other infections
• HIV is a retrovirus with RNA as its genetic material
• contains enzyme reverse transcriptase which transcribes RNA to a single strand of DNA to produce single strand of DNA in host cell
• spread through unprotected sex, sharing bodily fluids

Question 4

Influenza

Answer 4

• viral infection of ciliated epithelial cells in gas exchange system
• kills cells, leaving them open to secondary infection
• three main strands, A B and C
• A viruses are most virulent and are classified further by proteins on their surfaces
• flu viruses migrate regularly
• vulnerable groups are given vaccine

Question 5

Malaria

Answer 5

• caused by protoctista Plasmodium
• spread by bites of infected Anopheles mosquitoes
• Plasmodium parasite has complex life cycle with two hosts - mosquitoes and humans
• key is to control vector, which can be destroyed with insecticides and by removing standing water where they breed

Question 6

Ring worm

Answer 6

• fungal disease
• causes grey-white, crusty, infectious, circular areas of skin
• anti-fungal creams are an effective cure

Question 7

Athletes foot

Answer 7

• human fungal disease
• caused by a form of ringworm that grows on and digests the warm, moist skin between the toes
• causes cracking and scaling which may become itchy and sore
• anti-fungal creams are an effective cure